In aerobic cellular respiration, if four molecules of pyruvic acid enter steps two, the formation of acetyl CoA and three, the Krebs cycle, how many molecules of ATP, NADH, and FADH2 will be formed? a. 4 ATP, 16 NADH, 4 FADH2

b. 2 ATP, 8 NADH, 2 FADH2

c. 4 ATP, 12 NADH, 4 FADH2

d. 1 ATP, 4 NADH, 1 FADH2

4 ATP, 16 NADH, 4FADH2

Explanation:

Step 2: For two molecules of pyruvate that enter the transition reaction and form acetyl CoA, two molecules of NADH are produced. Therefore, four pyruvate molecules would lead to the formation of four molecules of NADH and four molecules of acetyl CoA.

Step 3: Each of this four acetyl CoA would enter the Krebs' cycle. For one molecule of acetyl CoA, 3 NADH and 1 FADH2 and 1 ATP are formed. Therefore, the four molecules of acetyl CoA would give rise to a total of 12 NADH, 4 FADH2, and 4 ATP molecules.

Total: This makes total 4 NADH from transition reaction + 12 NADH from Kreb's cycle, 4 FADH2, and 4 ATP molecules when four pyruvate molecules enter the second and third stages of aerobic cellular respiration.